This proposed work is oriented to define the ultramicroscopic alterations of diseased corneas, to study the cause of failure and alterations present in opaque corneal grafts, to study the endothelial alterations in experimental graft rejection - the function on T-lymphocytes in the graft reaction and to investigate the phenomena of bacterial adhesion to the corneal surface, and to ultramicrscopically study removed intraocular lenses.